Alexander michailowitsch nasttjkoit



Patented May 26, 1931 UNITED STATES. PATENT OFFICE ALEXANDER MIOHAILOWITSOH. N ASTUKOFF, OF MOSCOW, UNION OF SOCIALIST SOVIET REPUBLIOS PROCESS FOR THE PRODUCTION OF SYNTHETIC DRESSING OR TANNING MATERIALS No Drawing. Application filed November 1, 1928, Serial No. 316,613, and in the Union of Socialist Soviet Republics June 28, 1927.

The invention concerns a process for the production of synthetic tanning materials, wherein crude oil or its derivatives containing unsaturated cyclic hydrocarbons or solvent-naphtha are used as raw materials. It is known in tanning to use naphthenic and sulfo-napthenic acids and their condensation products in connection with formaldehyde, but in such processes the said hydrocarbons are not directly used as raw materials.

According to the invention, crude oil or its distillates or solvent-naphtha are condensed with sulfuric acid and formalin, wood pulp or glucose, and the condensates forming intermediate products, are oxidized or sulphonated after being neutralized and washed. The produced derivatives are soluble in water and possess the desired tanning qualities. They deposit gelatin or glue from its water solution, are, absorbed by skin powder (powdered beef skin) and transform the hide into tanned leather.

The following are some examples of the application of my process:

I. Crude oil of specific weight above 0.9 gin/emf, being a most suitable raw material, is transformed according to a known process by condensation with formalin and sulfuric acid (H SO into a so called formolite (see Holde,Kohle-nwasserstofle und Ole (Hydrocarbons and Oils), Berlin 1924). 7

One volume part of crude oil is for instance mixed with two volume parts of sulfuric acid, and gradually with vigorous shaking one volume part of formalin (a 40 percent Water solution of formaldehyde) is added. After cooling down water is added in abundance and a steam stream is blown through the liquid during one'or two hours. The precipitate is filtered off and washed. After neutralization and repeated washing the deposit, i. e. the formolite, is dried at about 100105 C., and the absorbed hydrocarbons are washed out by light benzene or petrol-ether. Hereby complete freedom of the formolite from absorbed oil is ensured. This is necessary, as even small quantities of oil are able to severely hinder the further transformation of the formolite into the tanning material.

The formolite is an intermediate product whiehby oxidation is transformed into the desired tanning material. The oxidation of the formolite is for instance effected in the following manner.

One weight part of formolite is diluted at 130 C. under pressure With 2.5 weight parts of nitric acid (HNO of a specific weight of 1.4, and oxidized with 30 parts of Water during 10 hours. The yield obtained amounts to about 90% of the formolite used. The product is filtered off and dissolved in diluted alkalis.

This solution precipitates glue or gelatin from their solutions, also it is absorbed from its solution by a skinpowder.

I claim:

1. In the process of producing synthetic tanning material, the step which consists in oxidizing by means of dilute nitric acid formolite obtained by condensing crude oil with sulfuric acid and formalin.

2. "In the process of producing synthetic tanning material, the step which consists in oxidizing by means of dilute nitric acid formolite obtained by condensing petroleum hydrocarbons containingunsaturated cyclic hydrocarbons, with sulfuric acid formalin.

8. In the process of producing synthetic tanning material, the step which consists in oxidizing by means of an oxidizing agent formolite obtained by condensing petroleum hydrocarbons with sulfuric acid and formalin. V i

4. In the process of producing synthetic and v tanning material, the step which consists in oxidizing by means of an oxidizing agent formolite obtained by condensing petroleum hydrocarbons with sulfuric acid and formalin, and dissolving the resultant product in an alkali solution.

5. In the process of producing synthetic tanning material, the step which consists in oxidizing by means of an oxidizing agent formolite obtained by condensing petroleum hydrocarbons with sulfuric acid and formalin, said oxidation being conducted at a super-atmospheric pressure.

(3. A tanning material, consisting of forinolite oxidized by an oxidizing agent and dissolved in an alkali solution.

7. A tanning material consisting of for-molite oxidized by a nitric acid solution.

In Witness whereof I affix my signature.

ALEXANDER M. NASTUKOFF. 

